=head1 NAME gcd - compute greatest common divisor of two integers=head1 SYNOPSIS gcd <a> <b>=head1 DESCRIPTIONThe B<gcd> program computes the greatest common divisor of twoarbitrary-precision integers I<a> and I<b>.  The result is written instandard decimal notation to the standard output.If I<b> is zero, B<gcd> will print an error message and exit.=head1 SEE ALSOinvmod(1), isprime(1), lap(1)=head1 AUTHOR Michael J. Fromberger <sting@linguist.dartmouth.edu> Thayer School of Engineering, Hanover, New Hampshire, USA  $Date: 2000/07/14 00:44:32 $